1. Field of the Invention
The present invention relates to an electron beam utilization system and, more particularly, to an electron beam utilization system and apparatus that readily permits the intermixing of batches of material to be subjected alternatively to electron or X-ray radiation.
2. Discussion of the Prior Art
The concept of irradiation of various products by electron beams is well established in the art and is utilized in many fields; for instance, sterilization and irradiation of plastics for various purposes.
Irradiation of products particularly food stuffs, by X-rays is discussed in an article by H. W. Kock and E. H. Eisenhower appearing in Publication #1273(1965) of the National Research Council of the National Academy of Sciences. This article discusses the relative merits for purposes of food treatment of gamma rays, electron beams, and X-rays generated by electron beams impinging on an appropriate target. The article infers that X-rays are useful for treating thick or bulk materials because of the ability of X-rays to penetrate to a much greater depth than electrons and gamma rays of comparable energy.
To date there are several commercial facilities and numerous in-house facilities providing electron beam irradiation for various purposes. Also, there are numerous in-house facilities for providing gamma radiation. To the knowledge of the inventor, there is only one commercial facility available providing both electron and X-radiation probably because of the cost of two such diverse pieces of costly commercial apparatus and the cost of housing two such large pieces of equipment that must be thoroughly shielded to prevent escape of dangerous levels of radiation.
A difficulty with operating a commercial X-ray facility for treatment of materials is heat generation. The target for converting electrons to X-rays must be water cooled regardless of the target. If the cooling water is lost for any reason, the target will be destroyed quite rapidly.
Further, certain relatively inexpensive high Z materials, such as lead, are not usable as targets in a fixed installation since the heat generated is too great for practical cooling. Such targets usually employ gold as the high Z material making the installation extremely expensive and incredible so if cooling water is lost which will occur on occasion.